Apparatus for grading pulverulent materials.



S. COOPER.

APPARATUS FOR. GRADING PUL'VBRULENT MATERIALS.

APPLICATION FILED JAN. 26. 1909.

933,532 Patented Sept. 7, 1909.

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UNITED STATES PATENT curios,

SIMON CC'GPER, OF NEW YQRK, "3., ASSIGNOR OF ONE-HALF TO CHARLES L.BERN- HEIM, 01" NE'W' YORK, N. Y.

Specification of Letters Patent.

Patented dept. 7, 1899.

Application filed January 26, 1909,, Serial No. 474,259.

T 0 all whom it only concern:

B it known that l, SIMON Coornu, a citizen ot' the United States,residing in the borough or lilanhattan, city, county, and litate ct YewYork, have. invented certain new and useful improvements in jipparas lusfor Grading Pulwrulent iii-a terial, of which the following is afull,:true, and con-' vise specification, from which others skilled inthe art will be able to'niahe, construct, and use the same.

The invention seeks to separate or assert pulverulent material intodifferent grades of fineness, by means of an ascending air column whichis made to actupon the material in opposition to the force of gravitythereon and to'select and carry out of the mass of the material suchparticles thereof as are sustainable upon the air current, and uttersuch selection, to carry the same forward for depositin any desiredmanner, or for further classification, for which purpose the currentproceeds with a diminishing velocity whereby on becoming gradually andsuccessively unsustainable on the current, according to their weight,the said particles fall into or are deposited in suitable receptaclessuccessively arranged for that purpose. in this manner it is sought tograde and classify finely divided or impalpable material continuouslyand with precision, separating it into any desired number of true gradesof fineness, that is to say, into grades whereof theparticles do notexceed in size a predetermined value and are substani' i ally un form.

The invention involves the disposition and relative arrangement ofapparatus for accompl cling the above results and certain features ofconstruction and operation there hereinafter explained and more parypointed out in the accompanying In the drawings forming a part hereof,Figure l is a vertical side elevation of a form of my apparatus, withparts broken away and shown in section; Fig. 2 is a transverse sectionalview through the several trunks of the apparatus; and 3 is a 1 diti ddetail.

The apparatus comprises, in combination, an upright imperforate trunk l,designated herein the main separating or classifying trunk, which may bemade of wooden boards,

as indicated, or of any suitable air-tight construction, and of anydesired crosssect1onal shape, provided it is adapted for a certainportion of its length to conduct an upward admission means com rises achamber 3 which as a matter of convenience is formed within and by thebase-portion of the cylindrical wall of the trunk, with its floor formedas a hopper which leads to an in clined discharge spout 4. Theair-chamber 3 is separated from the interior of the trunk proper bymeans of one or more transverse diaphragms 5, of perforated orforaminous construction adapted to admit air from the chamber to thetrunk, as later explained. Such air is supplied to the chamber throughan air-pipe 6 leading from a blower T or other suitable source of airpressure, andthe cubical capacity of the chamber is relatively large ascompared with the delivery of the blower so that the chamber will serveas an air reservoir or collector of suilicient volume to absorb orneutralize slight variations in the blower, or the pulsations caused byits revolving fan-blades and so that the pressure of the air below thediaphragms shall be substantially or generally the same at all points inorder to promote an even and uniform upward passage or" air through thelatter. In the practical operation of the apparatus this considerationis important. F or increasing the capacity of the chamber, itsdimensions may be extended farther than the boundaries of the trunk, orit may be connected with other air receptacles adapted for the stora 'eor air. The air thus passing upwardly tnrough the toraminous diaphragmsis divided into a number of more orless equal jets, and such dillerencesof pressure as may have previously existed beneath the diaphragms, ifnot equalized and diffused after passing the first of the diaphragmsbecomes so in any event in the region immediately above them, so that anascending column of air is sooner or later produced which has asubstantially unifornr motion. The total of the openings in at leastone, preferably the upper, of the diaphragms should preferably notexceed more than twenty per cent. of its total exposed area, and thesaid openings should be of uniform size and uniformly distributed sothat finely divided and uniform jets will be produced at all points. Theother diaphragms may be somewhat coarser. The preferred and mostserviceable size of the openings or per centage of total openings forthe finest of the diaphragms will depend somewhat on the nature, theweight and size of the material under treatment, being preferably fineror a lower percentage of opening for less weight or size, and viceversa, coarse burlap being suitable for many materials. The region ofpressure equalization or adjustment which exists immediately above thediaphragms extends upwardly more or less, depending upon the pressure ofthe air in the air-collecting chamber and the fineness and number of thediaphragms, and gradually merges into and forms the air column abovereferred to, of uniform and constant velocity, ascending within thetrunk and passing out through the upper outlet. The material to begraded is fed into the air current and distributed, preferably in theline of the longitudinal axis of the trunk, at a point above thediaphragms, and in or above the aforesaid region of pressure adjustmentwhere the multiplicity of fine jets from the upper diaphragm arebecoming merged into the column of constant velocity.

The invention includes and prefers a distributer apparatus whichconsists of an upright shaft 8, power-driven and appropriately journaledas indicated in the longitudinal axis of the trunk and carrying a numberof fine beater-blades 9 designed to produce as slight air disturbance inthe trunk as possible. These blades revolve directly beneath thedelivery of the feed-ohute or spout 10, which leads from the feed hopper11 through a suitable rotary feeding device 12, consisting, for example,of a usual conveyer wheel revolving within a casing and adapted toprevent back flow of air and powdered material through the spout. Thisfeeding device is driven by suitable gearing, not specifically shown,and is susceptible of regulation so as to feed in material as required.The conveyer 13, of ordinary construction may supply the feed-hopper 11with tailings from the tailings spout or any other source, the saidconveyer, like the feeding wheel, being intended to be driven in anyconvenient manner and to be also susceptible of regulation. The materialfed and distributed by the beater 9 as above described, is encounteredby the upward air current and those particles which by reason of theirsize or weight or both, are not sustainable on the particularpretermined veteases locity of current, fall more or less promptly uponand through the fine apertures in the diaphragms and into theair-collecting chamber 3, from which they may pass out as tailing'sthrough the spout 4, which latter is provided with fiap valve 14: orsome equivalent arrangement to prevent also the escape of air. Some ofthe finer particles may adhere to the tailings and also pass into thehopper, on which account the deposit in the latter may be returnedthrough the main trunk one or more times, as required for thoroughseparation. The remaining and finer particles, being those which are forthe most part sustainable, on the particular cur rent velocity in thetrunk and which succeed in reaching the point where the air column takeson its uniform and constant velocity, are carried upwardly therebytoward the upper outlet of the trunk, but those which are notindefinitely sustainable on the said current will fall back with thetailings before the outlet is reached so that only a certain definitemaximum grade size can pass out from the upper outlet, as predeterminedby the velocity of the constant air column, it being characteristic ofthis invention that the classifying trunk is so proportioned that thesaid column is of sufficient length and velocity as to allow all suchundesirable particles to fall back of their own weight before the outletis reached. After this selection has been fully accomplished, it is onlyessential that the velocity of the current shall not thereafter bediminished until the outlet has been passed. The proportions of thetrunk, and particularly the length thereof, may be varied, according tothe kind or quality of the material to be treated, and will havegenerally and desirably a greater length for materials of lighterspecific gravity or in which the tailings and the air-selected particlesare very closely related in size and considerable length will ordinarilybe the most satisfactory. The proportions of trunk illustrated in thedrawings are such as are suitable for material like ordinary talc powderor ground quartz. The velocity of the .air column may be regulated tocontrol the maximum grade size which it is desired shall pass out of theupper outlet for further classification and assortment, the saidvelocity being the primary controlling factor of the classifying orseparating process.

The column of air -with its burden of selected particles, on leaving theupper outlet 2, enters a filtering conduit wherein its velocity isgradually diminished by the continuing filtration of air through thetextile material of which the walls of the said conduit are formed. Thisfiltering conduit is arranged in a series of pairs of upright filteringtrunks successively connected at top and bottom and supplied withhoppers at 1 their bottom connections. In the first pair,

then-ext pair if filter mg truinrs i:

23, and in commnnicution adi-iering to the inner side of renchii avelocity so diminished the nitration that the maximum Elf- 36 particleswhich it capable of sustaining and carrying over to somewha' finer grades r-ze then the 1mm; ium that cussed through the outlet The particles orfiltered from the air during falling out the p sage through the tintpair of trunks constitute the first and largest grade size and full orare collected in the hopper 17 disposed at the bottom of the trunks forthat purpose and from which withdrawal may be made as inoiciited. in thenext pair of filtering trunks. 18 and 19, a similar selecrepeated, astill snniller naxinnun particles being sustainable at the outof tile t"unit if) and of each of the folowing upwurd filtering trunks, and soon, sothet successively liner grades are. collected in the hopper '20and in the successive hoppers, until the motion of the original uircurrent has been practically dissipated in a final trur 21, where thefinest of the is depoa ted in its hopper The particles filtered on o theair which escapes through I in the several l fil'ering walls trunle lwhich may cling to the fabric, are disloc .by means of a series ofclez'u'iers and fall into the hoppers. 'lhese cleaners are shown inFigs. 1 and as consisting of hoois or rin s 23 embracing each of thefiltering trunks and assembled in a supporting frame and mechanicallyguided and reciprocate t in light rubbin contact with the outside of thetextile walls of the trunss. T he drawing illust ates a harness of cordsend sheaves operated fron'i a Windlass by which the frame and cleanerrings can be raised {and Lowered either by hand or power, but anysuitable method may be employed for this purpose. T he cleaner ring ormember 2-3 is former of sufficient width or dinienrion in the directionof its movement to trap 1 him of air between it and the textile wellupon uover which it mo es,

and by "he compression of the said air film the ring up the counterpressure acting 1st ind through the fabric which el lect form 0 2dislodgnient. A. n'eferrtd cleaner apparatu consists of circular or 4'herwise reciprocating frame 2%, inste the material the walls by inc-ansof :-ounter pressure. butv withoiiit physical contact or wear thereupon.

The relation of the several grade sizes produced by theT'21l)'O"9tleSCllbed =appa' 'atus will and down, tl-icreby dislodging rA L i under tr rials, less than 200 niet-eln and, by virtue of theconstant movement: and uniform velocity of the air column and the modeof introduction of the material, as above described, enables suchmaterials to be s pia 'ated into a series of I tinct grades of finenesshaving uniformity of size then has hitherto been possible withair-flotation apparatus.

I claim as my invention the following 1. In apparatus for gradingpulverulent materials, an upright trunk having air-admission 'means atits base, comprising one or more air-diffusing and pressure-equalizingdiaphragms, and an outlet for dust-laden ai at its top and being closedagainst the entrance or escape of air between said diaphragm andair-outlet and being further of uniform crosssectional area and ofsufficient length between said diaphragm and outlet to enable aclassifying current of air admitted, and rising therein, to assume aconstant and uniform velocity within the trunk in combination with meansfor feeding the material to be graded into the air current, above thesaid diuphagm, an airliltering conduit connected with the outlet at thetop of said trunk for gradually diminishing the velocity of said aircurrent and comprising a series of classifying trunks formed withair-filtering walls and successively connected in tandem relation witheach other and with said upper outlet, and receptacles at the ends ofsaid trunks adapted to receive successively smaller grades of theclassified material.

2. In apparatus for grading pulverulent material an upright trunk havingan air inlet and tailings receptacle at its bottom and an outlet fordust -laden air at its top, and being closed against the entrance orescape of air between said 'air inlet and outlet, and being further ofuniform crosssectional area and 0f sutlicient length between said inletand outlet to enable a classifying current of air introduced and risingtherein to assume a constant and uniform velocity within the t unk, incombination with a feeding means comprising a chute closed against thepassage of mi air current and mounted to conduct the material to begraded into the interior of said trunk at or above the place thereinwhere the air currentbeoomes constant and uniform a posimaterials, anupright imperforate separating trunk having a tailings hopper and airinlet at its bottom and an upper outlet for dust-laden air and beingclosed against entrance or escape of air between said inlet I and outletand being of uniform cross-sectional area between said inlet and outlet,in combination with means for producing an ascending current of constantand uniform velocity through said trunk, comprising a blower pipe, anair chamber in the base of the trunk of relatively large cubicalcapacity with reference to said pipe, and a foraminous air-difiusing andpressure-equalizing diaphragm, dividing said chamber from the trunk andtransmitting the air therefrom upwardly into the trunk, and means,closed against the passage of air currents, for introducing the materialto be graded into the path of said upwardly ascending air.

4. In apparatus for grading pulverulent materials, an uprightimperforate separating trunk having a tailings hopper chamber in itsbase and an upper outlet for dustladen air, and being closed againstentrance or escape of air between said hopper chamber and upper outletand being of uniform cross-sectional area between said hopper chamberand outlet, means for producing an ascending current of uniform andconstant velocity upwardly within said trunk, comprising an air inletpipe leading from a suitable fan or blower to the hopper chamber, thelatter being of relatively greater diameter than said air inlet pipe,and one or more foraminous air-diffusing and pressure-equalizingdiaphragms dividing said trunk from the said hopper chamber andadmitting air from said chamber upwardly into and through said trunk, incombination with a filtering conduit connected with the said upperoutlet.

In an apparatus for grading pulverulent materials, an uprightimperforate separating trunk having an outlet for dustladen air at itstop and a tailings hopper at its base, and two or more foraminousdiaphragins superposed one above the other and separating said hopperand trunk, said trunk being of uniform cross-sectional area and alsoclosed against the entrance or escape of air between said upper outletand the said superposed diaphragms and being of sufficient lengthbetween said outlet and diaphragms to enable the air rising through thelatter to assume a constant and uniform velocity within said trunk, incombination with means for feeding the material to be graded into saidtrunk above the said superposed diaphragms.

6. In apparatus for grading pulverulent materials, an upright separatingtrunk, having air admission means at its base and an outlet for dustladen air at its top, and being closed against the entrance or escape ofair bet-ween said air admission means and outllet, and being further ofuniform crosssectional area between said parts and of sufficient lengthbetween said parts to enable a classifying current of air enteringtherein to assume constant and uniform velocity within the trunk, thesaid air admission means comprising one or more air-diffusing andpressure-equalizing foraminous dia phragms through which the air issuesupwardly into said trunk, in combination with means closed against theentrance or escape of air for feeding the material to be graded intosaid trunk and a filtering conduit connected with said upper outlet,comprised of a plurality of upright classifying trunks formed withtextile filtering walls alternately connected by their tops and bases intandem relation, and grade receptacles at the junctions of the bases ofsaid trunks.

7. In an apparatus for grading pulverulent materials, a separating trunkhaving an outlet for dust-laden air at the top and one or more airdiffusing and pressure equalizing diaphragms at its base forming apartition between the main part of said trunk and an air inlet chamber,the said trunk above the said chamber and below the upper air outletbeing closed against the entrance or escape of air, and the saiddiaphragm having not more than 20% of its total exposed area constitutedof uniformly distributed openings, through which the air passes fromsaid chamber upwardly into the said trunk,

in combination with means for feeding the material to be graded into themain part of said trunk above the said diaphragm therein.

8. In apparatus for grading pulverulent material, an upright separatingtrunk having an air outlet at its top and an air inlet at its bottom andbeing of uniform crosssectional area and also closed against theentrance or escape of air between said inlet and outlet, one or moreair-diffusing and pressure-equalizing diaphragms disposed across saidtrunk and dividing the lower part thereof into an air chamber, incombination with a feed chute closed against the passage of air andleading from the exterior of said trunk to approximately the centralaxis thereof and a power-driven distributer revoluble beneath thedelivery of said chute.

9. In apparatus for grading pulverulent material, an upright separatingtrunk having an air outlet at its top and air inlet at its bottom andbeing of uniform crossseotional area and closed against escape orentrance of air between said inlet and outlet, one or more air-diffusingand pressureequalizing diaphragms disposed across said trunk, dividingthe lower part thereof into an air chamber, and having 20% or less oftheir total exposed area constituted of air o]oenin; 2;.s, and means forfeeding the material to be graded into said trunk above said diaphragmor diaphragms, in combination with an air filtering conduit comprising aseries of upright filtering trunks having textile walls and connected intandem relation with said upper outlet of the trunk and means for thereception of the different grades at the bases of said upright filteringtrunks.

10. In apparatus for grading pulverulent material, the combination withan air-filtering trunk, formed with textile walls, of

a cleansing device, for said walls comprising a movable, tubular member,embracing the exterior of said trunk, and provided with one or moreorifices directed toward said trunk, means for supplying compressed airto said member, and means for reciprocating the same over, but not incontact with the surface of said walls.

In testimony whereof, I have signed my name to the specification in thepresence of two subscribing witnesses.

SIMON COOPER. iVitnesses CLIFFORD H. KLos, H. G. KIMBALL.

